Where does “pown” come from?

pown (English) comes from Middle English pounen, from Old English pūnian, from Proto-Germanic pūnōną — to break to pieces, pulverise.

Ancestry of “pown”, step by step

Step	Language	Word	Meaning
1	Middle English	pounen	To pound to dust; to powder by crushing; To...
2	Old English	pūnian	to pound, beat, bray, bruise, crush; to pound,...
3	Proto-Germanic	pūnōną	to break to pieces, pulverise